/* ================================================================
   Knowledge Check — bkbg-kc-*
   ================================================================ */

.bkbg-kc-block {
    border: 1px solid;
    padding: 24px;
    box-sizing: border-box;
}

.bkbg-kc-style-flat {
    border-color: transparent !important;
    background: transparent !important;
}

.bkbg-kc-style-minimal {
    border-color: transparent !important;
    padding: 0;
}

/* ── Header ───────────────────────────────────────────────────── */
.bkbg-kc-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 14px;
}

.bkbg-kc-icon {
    font-size: 24px;
    line-height: 1;
    flex-shrink: 0;
}

.bkbg-kc-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.bkbg-kc-topic {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .06em;
    text-transform: uppercase;
    border: 1px solid currentColor;
    padding: 2px 8px;
    border-radius: 20px;
}

.bkbg-kc-difficulty {
    font-size: 11px;
    color: #64748b;
    background: #f1f5f9;
    padding: 2px 8px;
    border-radius: 20px;
}

/* ── Question ─────────────────────────────────────────────────── */
.bkbg-kc-question {
    font-family:      var(--bkbg-kc-q-font-family, inherit);
    font-size:        var(--bkbg-kc-q-font-size-d, 17px);
    font-weight:      var(--bkbg-kc-q-font-weight, 700);
    font-style:       var(--bkbg-kc-q-font-style, normal);
    text-decoration:  var(--bkbg-kc-q-text-decoration, none);
    text-transform:   var(--bkbg-kc-q-text-transform, none);
    line-height:      var(--bkbg-kc-q-line-height-d, 1.5);
    letter-spacing:   var(--bkbg-kc-q-letter-spacing-d, normal);
    word-spacing:     var(--bkbg-kc-q-word-spacing-d, normal);
    margin: 0 0 18px;
}

/* ── Options ──────────────────────────────────────────────────── */
.bkbg-kc-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 18px;
}

.bkbg-kc-option {
    display: flex;
    align-items: center;
    gap: 10px;
    border: 1px solid;
    padding: 10px 14px;
    cursor: pointer;
    transition: background .15s, transform .1s;
    position: relative;
    font-family:      var(--bkbg-kc-o-font-family, inherit);
    font-size:        var(--bkbg-kc-o-font-size-d, 15px);
    font-weight:      var(--bkbg-kc-o-font-weight, 400);
    font-style:       var(--bkbg-kc-o-font-style, normal);
    text-decoration:  var(--bkbg-kc-o-text-decoration, none);
    text-transform:   var(--bkbg-kc-o-text-transform, none);
    line-height:      var(--bkbg-kc-o-line-height-d, 1.5);
    letter-spacing:   var(--bkbg-kc-o-letter-spacing-d, normal);
    word-spacing:     var(--bkbg-kc-o-word-spacing-d, normal);
}

.bkbg-kc-option:hover {
    filter: brightness(.97);
    transform: translateX(2px);
}

.bkbg-kc-option.is-selected {
    border-width: 2px;
    padding: 9px 13px;
}

.bkbg-kc-option.is-correct {
    border-width: 2px;
}

.bkbg-kc-option.is-incorrect {
    border-width: 2px;
}

/* Preview: show correct answer in editor */
.bkbg-kc-option.is-correct-preview {
    border-width: 2px;
}

.bkbg-kc-opt-letter {
    flex-shrink: 0;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
}

.bkbg-kc-opt-text {
    flex: 1;
}

.bkbg-kc-correct-badge {
    font-weight: 700;
    margin-left: auto;
}

/* ── Explanation ──────────────────────────────────────────────── */
.bkbg-kc-explanation {
    padding: 12px 16px;
    font-size: 14px;
    line-height: 1.65;
    margin-bottom: 16px;
    display: none;
}

.bkbg-kc-explanation.is-visible {
    display: block;
}

/* Editor: always show */
.bkbg-kc-block .bkbg-kc-explanation {
    display: block;
    opacity: .75;
}

/* ── Result badge ─────────────────────────────────────────────── */
.bkbg-kc-result {
    font-family:      var(--bkbg-kc-r-font-family, inherit);
    font-size:        var(--bkbg-kc-r-font-size-d, 15px);
    font-weight:      var(--bkbg-kc-r-font-weight, 700);
    font-style:       var(--bkbg-kc-r-font-style, normal);
    text-decoration:  var(--bkbg-kc-r-text-decoration, none);
    text-transform:   var(--bkbg-kc-r-text-transform, none);
    line-height:      var(--bkbg-kc-r-line-height-d, 1.4);
    letter-spacing:   var(--bkbg-kc-r-letter-spacing-d, normal);
    word-spacing:     var(--bkbg-kc-r-word-spacing-d, normal);
    margin-bottom: 10px;
    display: none;
}

.bkbg-kc-result.is-visible {
    display: block;
}

/* ── Actions ──────────────────────────────────────────────────── */
.bkbg-kc-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.bkbg-kc-reveal-btn,
.bkbg-kc-retry-btn {
    display: inline-flex;
    align-items: center;
    padding: 10px 24px;
    font-weight: 700;
    font-size: 14px;
    cursor: pointer;
    border: none;
    transition: opacity .15s, transform .1s;
    user-select: none;
}

.bkbg-kc-reveal-btn:hover,
.bkbg-kc-retry-btn:hover {
    opacity: .88;
    transform: translateY(-1px);
}

.bkbg-kc-retry-btn {
    background: #f1f5f9 !important;
    color: #475569 !important;
    display: none;
}

.bkbg-kc-retry-btn.is-visible {
    display: inline-flex;
}

/* ── Option editor (Inspector) ────────────────────────────────── */
.bkbg-kc-opt-editor {
    border-left: 3px solid;
    padding: 6px 0 6px 10px;
    margin-bottom: 6px;
}

.bkbg-kc-opt-editor-row {
    display: flex;
    align-items: center;
    gap: 6px;
}

.bkbg-kc-opt-editor-letter {
    flex-shrink: 0;
    font-weight: 700;
    font-size: 13px;
    color: #64748b;
    width: 16px;
}

/* ── Responsive typography ────────────────────────────────────── */
@media (max-width: 1024px) {
    .bkbg-kc-question {
        font-size:      var(--bkbg-kc-q-font-size-t, var(--bkbg-kc-q-font-size-d, 17px));
        line-height:    var(--bkbg-kc-q-line-height-t, var(--bkbg-kc-q-line-height-d, 1.5));
        letter-spacing: var(--bkbg-kc-q-letter-spacing-t, var(--bkbg-kc-q-letter-spacing-d, normal));
        word-spacing:   var(--bkbg-kc-q-word-spacing-t, var(--bkbg-kc-q-word-spacing-d, normal));
    }
    .bkbg-kc-option {
        font-size:      var(--bkbg-kc-o-font-size-t, var(--bkbg-kc-o-font-size-d, 15px));
        line-height:    var(--bkbg-kc-o-line-height-t, var(--bkbg-kc-o-line-height-d, 1.5));
        letter-spacing: var(--bkbg-kc-o-letter-spacing-t, var(--bkbg-kc-o-letter-spacing-d, normal));
        word-spacing:   var(--bkbg-kc-o-word-spacing-t, var(--bkbg-kc-o-word-spacing-d, normal));
    }
    .bkbg-kc-result {
        font-size:      var(--bkbg-kc-r-font-size-t, var(--bkbg-kc-r-font-size-d, 15px));
        line-height:    var(--bkbg-kc-r-line-height-t, var(--bkbg-kc-r-line-height-d, 1.4));
        letter-spacing: var(--bkbg-kc-r-letter-spacing-t, var(--bkbg-kc-r-letter-spacing-d, normal));
        word-spacing:   var(--bkbg-kc-r-word-spacing-t, var(--bkbg-kc-r-word-spacing-d, normal));
    }
}
@media (max-width: 767px) {
    .bkbg-kc-question {
        font-size:      var(--bkbg-kc-q-font-size-m, var(--bkbg-kc-q-font-size-t, var(--bkbg-kc-q-font-size-d, 17px)));
        line-height:    var(--bkbg-kc-q-line-height-m, var(--bkbg-kc-q-line-height-t, var(--bkbg-kc-q-line-height-d, 1.5)));
        letter-spacing: var(--bkbg-kc-q-letter-spacing-m, var(--bkbg-kc-q-letter-spacing-t, var(--bkbg-kc-q-letter-spacing-d, normal)));
        word-spacing:   var(--bkbg-kc-q-word-spacing-m, var(--bkbg-kc-q-word-spacing-t, var(--bkbg-kc-q-word-spacing-d, normal)));
    }
    .bkbg-kc-option {
        font-size:      var(--bkbg-kc-o-font-size-m, var(--bkbg-kc-o-font-size-t, var(--bkbg-kc-o-font-size-d, 15px)));
        line-height:    var(--bkbg-kc-o-line-height-m, var(--bkbg-kc-o-line-height-t, var(--bkbg-kc-o-line-height-d, 1.5)));
        letter-spacing: var(--bkbg-kc-o-letter-spacing-m, var(--bkbg-kc-o-letter-spacing-t, var(--bkbg-kc-o-letter-spacing-d, normal)));
        word-spacing:   var(--bkbg-kc-o-word-spacing-m, var(--bkbg-kc-o-word-spacing-t, var(--bkbg-kc-o-word-spacing-d, normal)));
    }
    .bkbg-kc-result {
        font-size:      var(--bkbg-kc-r-font-size-m, var(--bkbg-kc-r-font-size-t, var(--bkbg-kc-r-font-size-d, 15px)));
        line-height:    var(--bkbg-kc-r-line-height-m, var(--bkbg-kc-r-line-height-t, var(--bkbg-kc-r-line-height-d, 1.4)));
        letter-spacing: var(--bkbg-kc-r-letter-spacing-m, var(--bkbg-kc-r-letter-spacing-t, var(--bkbg-kc-r-letter-spacing-d, normal)));
        word-spacing:   var(--bkbg-kc-r-word-spacing-m, var(--bkbg-kc-r-word-spacing-t, var(--bkbg-kc-r-word-spacing-d, normal)));
    }
}